On 2026/3/7 14:28, Nithurshen wrote:
Currently, using --blobdev to specify an extra device is restricted from
working with the block map chunk format. This was previously noted as a task
that could be implemented by mapping the device blocks using a global address.
This patch implements this support by allowing the block map to reference
chunks residing on extra devices. This is achieved by:
1) Removing the -EINVAL check in mkfs/main.c that blocked this
combination of flags.
2) Calculating the global startblk address for the block map by summing
the blocks of the primary device and any preceding extra devices.
3) Ensuring that EROFS_CHUNK_FORMAT_INDEXES is only set if the user has
not forced the block map format, and adjusting the index unit size to
EROFS_BLOCK_MAP_ENTRY_SIZE accordingly.
4) Updating erofs_inode_fixup_chunkformat to correctly identify when
48-bit addressing is required for a block-mapped file on an extra device.
Hi Nithurshen,
Each line of the commit message must not exceed 72 characters.
Signed-off-by: Nithurshen <[email protected]>
---
lib/blobchunk.c | 34 ++++++++++++++++++++++++++++------
mkfs/main.c | 7 -------
2 files changed, 28 insertions(+), 13 deletions(-)
diff --git a/lib/blobchunk.c b/lib/blobchunk.c
index 96c161b..2ef7462 100644
--- a/lib/blobchunk.c
+++ b/lib/blobchunk.c
@@ -159,7 +159,17 @@ void erofs_inode_fixup_chunkformat(struct erofs_inode
*inode)
if (chunk->blkaddr == EROFS_NULL_ADDR)
continue;
if (chunk->device_id) {
- if (chunk->blkaddr > UINT32_MAX) {
+ if (!(inode->u.chunkformat &
EROFS_CHUNK_FORMAT_INDEXES)) {
+ erofs_blk_t mapped_blkaddr =
inode->sbi->primarydevice_blocks;
+ unsigned int i;
+
+ for (i = 0; i < chunk->device_id - 1; i++)
+ mapped_blkaddr +=
inode->sbi->devs[i].blocks;
+ if (mapped_blkaddr + chunk->blkaddr >
UINT32_MAX) {
+ _48bit = true;
It's impossible for 32-bit block map entries to support 48bit mode.
I think we should err out instead of enabling 48bit here.
BTW, it seems the erofs-utils codebase could not read a chunk-based
EROFS image
with block map and extra devices (but in-kernel implementation could),
as erofs_map_dev() does
not reset m_deviceid. Could you help also fix this? If you are
interested please also add related
testcases in erofs/erofsnightly repo.
Thanks,
Yifan Zhao
+ break;
+ }
+ } else if (chunk->blkaddr > UINT32_MAX) {
_48bit = true;
break;
}
@@ -201,8 +211,16 @@ int erofs_write_chunk_indexes(struct erofs_inode *inode,
struct erofs_vfile *vf,
if (chunk->blkaddr == EROFS_NULL_ADDR) {
startblk = EROFS_NULL_ADDR;
} else if (chunk->device_id) {
- DBG_BUGON(!(inode->u.chunkformat &
EROFS_CHUNK_FORMAT_INDEXES));
- startblk = chunk->blkaddr;
+ if (inode->u.chunkformat & EROFS_CHUNK_FORMAT_INDEXES) {
+ startblk = chunk->blkaddr;
+ } else {
+ unsigned int i;
+
+ startblk = sbi->primarydevice_blocks;
+ for (i = 0; i < chunk->device_id - 1; i++)
+ startblk += sbi->devs[i].blocks;
+ startblk += chunk->blkaddr;
+ }
extent_start = EROFS_NULL_ADDR;
} else {
startblk = remapped_base + chunk->blkaddr;
@@ -324,7 +342,7 @@ int erofs_blob_write_chunked_file(struct erofs_inode
*inode, int fd,
chunksize = 1ULL << chunkbits;
count = DIV_ROUND_UP(inode->i_size, chunksize);
- if (sbi->extra_devices)
+ if (sbi->extra_devices && cfg.c_force_chunkformat !=
FORCE_INODE_BLOCK_MAP)
inode->u.chunkformat |= EROFS_CHUNK_FORMAT_INDEXES;
if (inode->u.chunkformat & EROFS_CHUNK_FORMAT_INDEXES)
unit = sizeof(struct erofs_inode_chunk_index);
@@ -494,8 +512,12 @@ int tarerofs_write_chunkes(struct erofs_inode *inode,
erofs_off_t data_offset)
inode->u.chunkformat |= chunkbits - sbi->blkszbits;
if (sbi->extra_devices) {
device_id = 1;
- inode->u.chunkformat |= EROFS_CHUNK_FORMAT_INDEXES;
- unit = sizeof(struct erofs_inode_chunk_index);
+ if (cfg.c_force_chunkformat != FORCE_INODE_BLOCK_MAP)
+ inode->u.chunkformat |= EROFS_CHUNK_FORMAT_INDEXES;
+ if (inode->u.chunkformat & EROFS_CHUNK_FORMAT_INDEXES)
+ unit = sizeof(struct erofs_inode_chunk_index);
+ else
+ unit = EROFS_BLOCK_MAP_ENTRY_SIZE;
DBG_BUGON(erofs_blkoff(sbi, data_offset));
blkaddr = erofs_blknr(sbi, data_offset);
} else {
diff --git a/mkfs/main.c b/mkfs/main.c
index 58c18f9..07ef086 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -1565,13 +1565,6 @@ static int mkfs_parse_options_cfg(struct
erofs_importer_params *params,
return -EINVAL;
}
- /* TODO: can be implemented with (deviceslot) mapped_blkaddr */
- if (cfg.c_blobdev_path &&
- cfg.c_force_chunkformat == FORCE_INODE_BLOCK_MAP) {
- erofs_err("--blobdev cannot work with block map currently");
- return -EINVAL;
- }
-
if (optind >= argc) {
erofs_err("missing argument: FILE");
return -EINVAL;
